Cover arrangement

ABSTRACT

A cover arrangement for closing at least part of the opening of a wheel well for a retractible landing gear of an aircraft. The cover arrangement has one or more units, each incorporating a cover plate and an engaging arm which extends generally at right angles to the plane of the cover plate. The unit is pivotably mounted at the edge of the opening for movement between open and closed positions. In the closed position, the arm extends into the wheel well and the cover plate closes at least part of the opening of the wheel well and is in the path of travel of the landing gear when the latter is lowered, and in the open position the cover plate is outside of the opening and the arm is in the path of travel of the landing gear when the latter is retracted. Consequently, the unit is pivoted into its open position by the landing gear when the same is lowered, and is pivoted into its closed position by the landing gear when the same is retracted. Spring means are provided which hold the unit in open position when the landing gear is in its lowered position and in closed position when the landing gear is in its retracted position.

United States Patent Riedl 1 Mar. 7, 1972 [54] COVER ARRANGEMENT Franz Riedl, Munich, Germany [73] Assignee: Vereinigte Flugtechnische Werke Gmbfl fruher Weser" Flugzeugbau am lFocke- Wull am Heinkel-Flugzeugbau, Bremen, Germany 22 Filed: Jan. 19,1970 [211 Appl.No.: 3,898

[72] Inventor:

Primary Examiner-Milton Buchler Assistant Examiner-Paul E. Sauberer Attorney-Spencer and Kaye [57] ABSTRACT A cover arrangement for closing at least part of the opening of a wheel well for a retractible landing gear of an aircrafi. The cover arrangement has one or more units, each incorporating a cover plate and an engaging arm which extends generally at right angles to the plane of the cover plate. The unit is pivotably mounted at the edge of the opening for movement between open and closed positions. In the closed position, the arm extends into the wheel well and the cover plate closes at least part of the opening of the wheel well and is in the path of travel of the landing gear when the latter is lowered, and in the open position the cover plate is outside of the opening and the arm is in the path of travel of the landing gear when the latter is retracted. Consequently, the unit is pivoted into its open position by the landing gear when the same is lowered, and is pivoted into its closed position by the landing gear when the same is retracted. Spring means are provided which hold the unit in open position when the landing gear is in its lowered position and in closed position when the landing gear is in its retracted position.

8 Claims, 4 Drawing Figures PATENTEDMAR (I972 3,647,186

sum 1 nr 2 mvm'mu- Frunz Riedl ATTORNEYS.

COVER ARRANGEMENT BACKGROUND OF THE INVENTION The present invention relates to a cover arrangement for closing at least part of the opening of a wheel well for a retractible landing gear of an aircraft, and particularly to a 'cover arrangement in which one or more spring-biased cover plates are pivotably mounted near the edge of the opening of the wheel well and close off the gap between the edge of the opening and the edge of the wheel of the landing gear, the arrangement of the parts being such that the landing gear forcibly carries the cover plate or plates along during lowering and retracting of the landing gear.

In conventional cover arrangement of the above type, the cover plate is pivoted through the intermediary of a positioning member, which is carried along by the landing gear as the same is retracted and which closes the cover, whereupon the cover is held in its closed position by means of a spring. In other arrangements of this type, the positioning member is constituted by an articulated strut which can be bent in against the action of a spring and which, in its extended position, holds the cover plate in its open position. In all such known arrangements, a relatively large number of individual parts are required, which contribute to increased expense and maintenance costs. Moreover, conventional cover arrangements of this type are so constructed that the spring holds the cover plate in its open position only.

In other cover arrangements, the cover plate is moved through the intermediary of a positioning arm which extends generally at right angles to the cover plate, which arm is engaged by the wheel when the landing gear is retracted so that the cover plate is moved to its closed position. In such arrangements, it is the wheel which holds the cover plate in its closed position, and only the wheel, this likewise being the case in the other, above-described arrangements. I

It is, therefore, the primary object of the present invention to provide a cover arrangement for the wheel well of a retractible landing gear of an aircraft, which avoids the above drawbacks, which is of simple and rugged construction, and in which the cover plate is safely held in its open position and its closed position in a manner which is completely independent of the landing wheel as such.

BRIEF DESCRIPTION OF THE INVENTION With the above object in view, the present invention resides, essentially, in a cover arrangement for closing at least a part of the opening of a wheel well for a retractible landing gear which itself is movable between lowered and retracted positions. In accordance with the present invention, the cover arrangement comprises one or more units, each incorporating a cover plate and an engaging arm which extends generally at right angles to the plane of the cover plate. The unit is pivotably mounted at the edge of the opening for movement between open and closed positions. In the closed position, the arm extends into the wheel well and the cover plate closes at least part of the opening of the wheel well and is in the path of travel of the landing gear when the latter is lowered, and in the open position the cover plate is outside of the opening and the arm is in the path of travel of the landing gear when the latter is retracted. Consequently, the unit is pivoted into its open position by the landing gear when the same is lowered, and is pivoted into its closed position by the landing gear when the same is retracted. Spring means are provided which hold the unit in open position when the landing gear is in its lowered position and in closed position when the landing gear is in its retracted position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of the retracted nose wheel of an aircraft incorporating a cover arrangement according to the present invention, part of the aircraft hull being shown in section.

FIG. 2 is a sectional elevational view, on an enlarged scale, showing the landing gear in its retracted position and one of the units of the cover arrangement in its closed position.

FIG. 3 is a sectional elevational view similar to FIG. 2 except that the landing gear, as shown in solid lines, is completely out of the wheel well and one of the units of the cover arrangement, as shown in solid lines, is in its open position, the landing gear and the unit also being shown, in phantom lines, in intermediate positions.

FIG. 4 is a bottom plan view of the entire cover arrangement, the same being shown with the landing gear in retracted position and the cover arrangement in closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, the same shows the nose of an aircraft which is provided with a wheel well which receives a retractible landing gear 2, the same comprising the nose wheel 3 and a rotatable shock absorber wheel strut 4. The landing gear 2 is lowered and retracted by means of an operating cylinder 5 having connecting studs 6 and 7 through which hydraulic fluid is moved into and out of the cylinder, the cylinder 5 being hinged at one end and the piston rod 5a which extends out of the other end of the cylinder being pivotably connected to a crank 40 which is joined to the strut 4, so that when hydraulic fluid is introduced through the stud 6, the strut 4 is pivoted about the axis 8, which is fixed with respect to the aircraft, and the landing gear is lowered, whereas when hydraulic fluid is introduced through the stud 7, the landing gear is retracted back into the wheel well.

The opening in the nose section of the fuselage behind which the wheel well is located is indicated at 9, and this opening is closed by the generally flat side 30 of the wheel and by cover plates 10 and 11 when the wheel is retracted. That is to say, the cover plates 10 and 11 close off the gap 12 between the edge of the wheel 3 and the edges of the opening 9.

Each cover plate 10 is part of a unit which is pivotably mounted near the edge of the opening 9 by means of an axle 13, the units being located at different respective stretches along the edge of the opening. Each unit has, besides the cover plate, an engagement arm 14 that extends generally at right angles to the plane of the cover plate, as well as a radially projecting nose 15 which is located outside of the axis of the axle l3 and which, when the unit is in closed position, projects toward the edge of the opening. Also provided is a compression spring device 17 one end of which is pivotably connected to the nose I5 by means of a pin 16, the other end ofthe spring device 17 being pivotably connected, by means of a further pin 19, to the free end of a stationary arm 18 which extends into the wheel well, the arm 18 itself being fixed to the aircraft.

The cover plate 11 is connected to the strut 4 of the landing gear 2 by way of a collapsible connecting member 20, in a manner well known in the art. In this way, the cover plate 11 moves together with the landing gear, i.e., the cover plate I l is in a position wherein it closes part of the opening when the landing gear is in its retracted position, the cover plate 11 being in its open position whenever the landing gear is in its lowered position.

As is readily apparent from the drawing, the arrangement of the above-described parts is such when each unit l0, 14, is in its closed position wherein the arm 14 extends into the wheel well and the cover plate 10 closes a part of the opening of the wheel, the cover plate I0 is in the path of travel of the landing gear, namely, the wheel 3, when the landing gear is being lowered, whereas when each unit is in its open position, the cover plate 10 is itself outside of the opening and the arm 14 is in the path of travel of the landing gear-again, the wheel 3 when the landing gear is being retracted. Consequently, each unit 10, I4 is pivoted into its open position by the landing gear when the same is lowered and is pivoted into its closed position by the landing gear when the landing gear is retracted. In

the course of the pivoting of each unit, the associated spring device 17 passes through a dead-center position, Le, a position in which the spring device acts along a line passing through the axis about which the respective unit 10, 14 pivots. Therefore, the spring device 17 is effective to hold the unit in its position, which is limited by the stationary abutment 21 fixed to the aircraft, as well as in the closed position in which the cover plate is pressed against the wheel 3, as well as in its open position which is limited by the stationary abutment 21.

Thanks to the above arrangement, there is obtained a cover arrangement which is composed of few parts, thus significantly reducing both the original construction costs as well as maintenance costs of the aircraft. Moreover, the cover plate unit is held in each of its two end positions by but a single spring device, so that the cover plate is positively locked in place without having to rely on any of the moving parts of the landing gear. Furthermore, thanks to the fact that, as described above, the spring acts on the radially projecting nose 15 which is located outside of the axis of the axle 13 and which, when the cover plate unit is in closed position, projects toward the edge of the opening, the entire spring force of the device 17 or at least a large component of the entire spring force, is available to hold the cover plate unit in each of its two end positions.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. For example, the invention is not limited for use in connection with the nose wheel of an aircraft but is equally applicable for use with the main landing gear as well.

lclaim:

1. In an aircraft, a cover arrangement for closing at least part of the opening of a wheel well for a retractible landing gear which itself is movable between lowered and retracted positions, the cover arrangement comprising, in combination:

a. at least one unit incorporating a cover plate and an engag ing arm which extends generally at right angles to the plane of said cover plate;

b. means pivotably mounting said unit at the edge of said opening for movement between a closed position wherein said arm extends into the wheel well and said cover plate closes at least part of the opening of the wheel well and is in the path of travel of the landing gear when the latter is lowered, and an open position wherein said cover plate is outside of said opening and said arm is in the path of travel of the landing gear when the latter is retracted, in consequence of which said unit is pivoted into its open position by the landing gear when the same is lowered and is pivoted into its closed position by the landing gear when the same is retracted; and

c. spring means operatively connected to the aircraft and to said unit for holding the latter in open position when the landing gear is in its lowered position and for holding said unit in closed position when the landing gear is in its retracted position, said spring means consisting of a single spring device which is connected to said unit at a point thereon that is located outside of the axis about which said unit is pivotably mounted by said mounting means and which, as said unit moves from its closed to its open position and vice versa, passes through a dead-center position wherein said spring device acts along a line passing through said pivot axis, said spring device thus constituting a means for holding said unit in its closed position as well as in its open position entirely independently of the landing gear.

2. A cover arrangement as defined in claim 1, wherein said single spring device comprises a compression spring.

3. A cover arrangement as defined in claim 1, wherein said unit further incorporates a nose which, when said unit is in its closed position, projects toward the edge of said opening, and

wherein said point at which said spring means are connected to said unit is located at said nose.

4. A cover arrangement as defined ll'l claim 3, further comprising a stationary arm arranged on the aircraft and having a free end extending into the wheel well, and wherein said spring means are connected to the aircraft at said free end of said stationary arm.

5. A cover arrangement as defined in claim 1, wherein the landing gear includes a wheel, and wherein, when said unit is in its closed position, said arm, is in the path of travel of the wheel when the gear is lowered and retracted, respectively.

6. In an aircraft, a cover arrangement for closing at least a part of the opening of a wheel well for a retractible landing gear which itself is movablebetween lowered and retracted positions, the cover arrangement comprising, in combination:

a. a plurality of units each incorporating a cover plate and an engaging arm which extends generally at right angles to the plane of said cover plate;

b. a plurality of means pivotably mounting said units, respectively, at different respective stretches along the edge of said opening for movement between closed positions wherein said arms extend into the wheel well and said cover plates close at least part of the opening of the wheel well and are in the path of travel of the landing gear when the latter is lowered, and an open position wherein said cover plates are outside of said opening and said arms are in the path of travel of the landing gear when the latter is retracted, in consequence of which said units are pivoted into open position by the landing gear when the same is lowered and are pivoted into closed position by the landing gear when the same is retracted; and

c. a plurality of spring means operatively connected to the aircraft and to respective ones of said units for holding the latter in open position when the landing gear is in its lowered position and for holding said units in closed position when the landing gear is in its retracted position, each of said spring means consisting of a single compression spring device which is connected to its respective unit at a point thereon that is located outside of the axis about which such unit is pivotably mounted by its respective mounting means and which, as such unit moves from its closed to its open position and vice versa, passes through a dead center position wherein the spring device acts along a dead-center position wherein such spring device acts along a line passing through such pivot axis, each spring device thus constituting a means for holding its respective unit in its closed position as well as in its open position entirely independently of the landing gear and of the other units.

7. A cover arrangement as defined in claim 6, wherein the landing gear includes a wheel having a generally flat side face which, when the landing gear is in its retracted position, lies in the plane of the opening, and wherein the cover arrangement further comprises a cover plate carried by the landing gear and movable therewith between a closed position when the landing gear is in its retracted position and an open position when the landing gear is in its lowered position, said last mentioned cover plate together with said cover plates of said units and said side face of the wheel closing substantially the entire opening when the landing gear is in its retracted position.

8. A cover arrangement as defined in claim 6, wherein each unit further incorporates a nose which, when the respective unit is in its closed position, projects toward the edge of said opening and which has thereon said point located outside of the axis about which the respective unit is pivotably mounted by the respective mounting means; wherein a plurality of stationary arms are provided, one for each respective unit, each stationary arm being fixedly mounted on the aircraft and having a free end extending into the wheel well; and wherein each spring device has one end connected to said point on the nose of the respective unit and the other end to the free end of the respective arm.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Paten No- 3.647.166 Dated March 7th. 1972 Inventor(g) Franz Riedl It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading of the patent, lines 4 and 5, change "Flugzeugbau am Focke-Wulf am Heinkel-Flugzeugbau" to -Flugzeugbau/Focke-Wulf/Heinkel-FlugZeugbau-.

Singed and sealed this 15th day of August 1972.

(SEAL) Attest:

EDWARD M. FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMWDC 6o376 p69 U.5. GOVERNMENT PRINTING OFFICE: I99 0-366-334 

1. In an aircraft, a cover arrangement for closing at least part of the opening of a wheel well for a retractible landing gear which itself is movable between lowered and retracted positions, the cover arrangement comprising, in combination: a. at least one unit incorporating a cover plate and an engaging arm which extends generAlly at right angles to the plane of said cover plate; b. means pivotably mounting said unit at the edge of said opening for movement between a closed position wherein said arm extends into the wheel well and said cover plate closes at least part of the opening of the wheel well and is in the path of travel of the landing gear when the latter is lowered, and an open position wherein said cover plate is outside of said opening and said arm is in the path of travel of the landing gear when the latter is retracted, in consequence of which said unit is pivoted into its open position by the landing gear when the same is lowered and is pivoted into its closed position by the landing gear when the same is retracted; and c. spring means operatively connected to the aircraft and to said unit for holding the latter in open position when the landing gear is in its lowered position and for holding said unit in closed position when the landing gear is in its retracted position, said spring means consisting of a single spring device which is connected to said unit at a point thereon that is located outside of the axis about which said unit is pivotably mounted by said mounting means and which, as said unit moves from its closed to its open position and vice versa, passes through a dead-center position wherein said spring device acts along a line passing through said pivot axis, said spring device thus constituting a means for holding said unit in its closed position as well as in its open position entirely independently of the landing gear.
 2. A cover arrangement as defined in claim 1, wherein said single spring device comprises a compression spring.
 3. A cover arrangement as defined in claim 1, wherein said unit further incorporates a nose which, when said unit is in its closed position, projects toward the edge of said opening, and wherein said point at which said spring means are connected to said unit is located at said nose.
 4. A cover arrangement as defined in claim 3, further comprising a stationary arm arranged on the aircraft and having a free end extending into the wheel well, and wherein said spring means are connected to the aircraft at said free end of said stationary arm.
 5. A cover arrangement as defined in claim 1, wherein the landing gear includes a wheel, and wherein, when said unit is in its closed position, said arm, is in the path of travel of the wheel when the gear is lowered and retracted, respectively.
 6. In an aircraft, a cover arrangement for closing at least a part of the opening of a wheel well for a retractible landing gear which itself is movable between lowered and retracted positions, the cover arrangement comprising, in combination: a. a plurality of units each incorporating a cover plate and an engaging arm which extends generally at right angles to the plane of said cover plate; b. a plurality of means pivotably mounting said units, respectively, at different respective stretches along the edge of said opening for movement between closed positions wherein said arms extend into the wheel well and said cover plates close at least part of the opening of the wheel well and are in the path of travel of the landing gear when the latter is lowered, and an open position wherein said cover plates are outside of said opening and said arms are in the path of travel of the landing gear when the latter is retracted, in consequence of which said units are pivoted into open position by the landing gear when the same is lowered and are pivoted into closed position by the landing gear when the same is retracted; and c. a plurality of spring means operatively connected to the aircraft and to respective ones of said units for holding the latter in open position when the landing gear is in its lowered position and for holding said units in closed position when the landing gear is in its retracted position, each of said spring means consisting of a single compression spring device which is connected to its respective unit at a Point thereon that is located outside of the axis about which such unit is pivotably mounted by its respective mounting means and which, as such unit moves from its closed to its open position and vice versa, passes through a dead center position wherein the spring device acts along a dead-center position wherein such spring device acts along a line passing through such pivot axis, each spring device thus constituting a means for holding its respective unit in its closed position as well as in its open position entirely independently of the landing gear and of the other units.
 7. A cover arrangement as defined in claim 6, wherein the landing gear includes a wheel having a generally flat side face which, when the landing gear is in its retracted position, lies in the plane of the opening, and wherein the cover arrangement further comprises a cover plate carried by the landing gear and movable therewith between a closed position when the landing gear is in its retracted position and an open position when the landing gear is in its lowered position, said last-mentioned cover plate together with said cover plates of said units and said side face of the wheel closing substantially the entire opening when the landing gear is in its retracted position.
 8. A cover arrangement as defined in claim 6, wherein each unit further incorporates a nose which, when the respective unit is in its closed position, projects toward the edge of said opening and which has thereon said point located outside of the axis about which the respective unit is pivotably mounted by the respective mounting means; wherein a plurality of stationary arms are provided, one for each respective unit, each stationary arm being fixedly mounted on the aircraft and having a free end extending into the wheel well; and wherein each spring device has one end connected to said point on the nose of the respective unit and the other end to the free end of the respective arm. 